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com.vaadin.flow.data.provider.
Class DataProviderWrapper<T,F,M>
- java.lang.Object
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- com.vaadin.flow.data.provider.DataProviderWrapper<T,F,M>
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Type Parameters:
T- data provider data typeF- wrapper query filter typeM- underlying data provider filter typeAll Implemented Interfaces:
DataProvider<T,F>,SerializableDirect Known Subclasses:
public abstract class DataProviderWrapper<T,F,M> extends Object implements DataProvider<T,F>Wrapper class for modifying, chaining and replacing filters and sorting in a query. Used to create a suitable
Queryfor the underlying data provider with correct filters and sorting.Since:
1.0.
Author:
Vaadin Ltd
See Also:
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Field Summary
Fields Modifier and Type Field Description protected DataProvider<T,M>dataProviderThe actual data provider behind this wrapper.
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Constructor Summary
Constructors Modifier Constructor Description protectedDataProviderWrapper(DataProvider<T,M> dataProvider)Constructs a filtering wrapper for a data provider.
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Method Summary
All Methods Modifier and Type Method Description RegistrationaddDataProviderListener(DataProviderListener<T> listener)Adds a data provider listener.
Stream<T>fetch(Query<T,F> t)Fetches data from this DataProvider using given
query.protected abstract MgetFilter(Query<T,F> query)Gets the filter that should be used in the modified Query.
ObjectgetId(T item)Gets an identifier for the given item.
booleanisInMemory()Gets whether the DataProvider content all available in memory or does it use some external backend.
voidrefreshAll()Refreshes all data based on currently available data in the underlying provider.
voidrefreshItem(T item)Refreshes the given item.
intsize(Query<T,F> t)Gets the amount of data in this DataProvider.
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface com.vaadin.flow.data.provider.DataProvider
refreshItem, withConfigurableFilter, withConfigurableFilter, withConvertedFilter
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Field Detail
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dataProvider
protected DataProvider<T,M> dataProviderThe actual data provider behind this wrapper.
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Constructor Detail
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DataProviderWrapper
protected DataProviderWrapper(DataProvider<T,M> dataProvider)Constructs a filtering wrapper for a data provider.
Parameters:
dataProvider- the wrapped data provider, notnull
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Method Detail
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isInMemory
public boolean isInMemory()Description copied from interface:
DataProviderGets whether the DataProvider content all available in memory or does it use some external backend.
Specified by:
isInMemoryin interfaceDataProvider<T,F>Returns:
trueif all data is in memory;falseif not
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refreshAll
public void refreshAll()Description copied from interface:
DataProviderRefreshes all data based on currently available data in the underlying provider.
Specified by:
refreshAllin interfaceDataProvider<T,F>
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refreshItem
public void refreshItem(T item)Description copied from interface:
DataProviderRefreshes the given item. This method should be used to inform all
DataProviderListenersthat an item has been updated or replaced with a new instance.For this to work properly, the item must either implement
Object.equals(Object)andObject.hashCode()to consider both the old and the new item instances to be equal, or alternativelyDataProvider.getId(Object)should be implemented to return an appropriate identifier.Specified by:
refreshItemin interfaceDataProvider<T,F>Parameters:
item- the item to refreshSee Also:
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getId
public Object getId(T item)Description copied from interface:
DataProviderGets an identifier for the given item. This identifier is used by the framework to determine equality between two items.
Default is to use item itself as its own identifier. If the item has
Object.equals(Object)andObject.hashCode()implemented in a way that it can be compared to other items, no changes are required.Note: This method will be called often by the Framework. It should not do any expensive operations.
Specified by:
getIdin interfaceDataProvider<T,F>Parameters:
item- the item to get identifier for; notnullReturns:
the identifier for given item; not
null
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addDataProviderListener
public Registration addDataProviderListener(DataProviderListener<T> listener)Description copied from interface:
DataProviderAdds a data provider listener. The listener is called when some piece of data is updated.
The
DataProvider.refreshAll()method firesDataChangeEventeach time when it's called. It allows to update UI components when user changes something in the underlying data.Specified by:
addDataProviderListenerin interfaceDataProvider<T,F>Parameters:
listener- the data change listener, not nullReturns:
a registration for the listener
See Also:
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size
public int size(Query<T,F> t)Description copied from interface:
DataProviderGets the amount of data in this DataProvider.
Specified by:
sizein interfaceDataProvider<T,F>Parameters:
t- query with sorting and filteringReturns:
the size of the data provider
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fetch
public Stream<T> fetch(Query<T,F> t)Description copied from interface:
DataProviderFetches data from this DataProvider using given
query.Specified by:
fetchin interfaceDataProvider<T,F>Parameters:
t- given query to request dataReturns:
the result of the query request: a stream of data objects, not
null
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